Method for treating wood

ABSTRACT

This invention is directed to a method for producing and preserving very light colored wooden objects such as utility poles, fence posts and piling timbers. These wooden objects are treated under heat and pressure with a composition comprising a blend of (I) a blend of (A) from about 1% to about 50% by weight of pentachlorophenol and (B) from about 99% to about 50% by weight of a petroleum oil and (II) from about 0.005% to about 100% by weight based upon the total weight of (I) of a compound containing a heavy metal oxide. Wood treating compositions of this invention are stable against discoloration and formation of sludge during storage and during the wood treating process.

Amundsen et a1.

METHOD FOR TREATING WOOD Inventors: Joseph Amundsen; William H.

Wetzel, both of Federal Way; Norma Naimy, Seattle; Robert J. Goodwin,Puyallup, all of Wash.

Reichhold Chemicals, Inc., White Plains, NY.

Filed: Mar. 6, 1974 Appl. No.: 448,543

Related US. Application Data Continuation of Ser. No, 244,877, April 17,1972, abandoned.

Assignee:

US. Cl. 427/297; 21/7; 427/298 Int. Cl B05c 3/00; B27k 3/08; B44d 1/26Field of Search 117/147, 116,119, 59,

References Cited UNITED STATES PATENTS June 10, 1975 3,070,494 12/1962Goldstein et a1 117/147 3,200,003 8/1965 Beschel 117/147 3,685,9598/1972 Dunn et al... 21/7 3,695,920 10/1972 Hill 117/147 3,702,784l1/1972 Farguhar et al. 21/7 Primary Examiner-William R. Trenor [57]ABSTRACT This invention is directed to a method for producing andpreserving very light colored wooden objects such as utility poles,fence posts and piling timbers. These wooden objects are treated underheat and pressure with a composition comprising a blend of (I) a blendof (A) from about 1% to about 50% by weight of pentachlorophenol and (B)from about 99% to about 50% by weight of a petroleum oil and (II) fromabout 0.005% to about 100% by weight based upon the total weight of (l)of a compound containing a heavy metal oxide. Wood treating compositionsof this invention are stable against discoloration and formation ofsludge during storage and during the wood treating process.

12 Claims, No Drawings METHOD FOR TREATING WOOD This is a continuationof Ser. No. 244.877, filed Apr. 17. 1972. now abandoned.

This invention discloses new wood treating methods and new inhibitorsystems for hydrocarbon oil compositions used in wood treating andpreserving; these inhibitors stabilize the treating mixture againstdiscoloration and formation of sludge during storage and during the woodtreating process. Wood treated with the compositions of this inventionare very light in appearance and the efficiency of the treatingoperations is improved. In general the wood treating compositionscomprise (I) a pentachlorophenol-hydrocarbon oil wood treating solutionincorporating those cosolvents, waxes, decolorants, inhibitors,surfactants and resins commonly used in the art and (II) from about0.005% to about 100% by weight of a compound containing a member of theclass of compounds classified in Groups lB, IIB, lIA. IVA. IVB, VIA,VIB, and VIII of the Periodic Table.*

*According to the style published by Fisher Scientific Corpv New York.New York under Catalog No. 5-702 W62).

Pentachlorophenol and oil solutions containing pentachlorophenol arewidely used in industry to preserve wood and to prevent or forestall rotand decay. The pentachlorophenol may be directly added to the petroleumhydrocarbon oil and dissolved or it may be prepared as a liquidconcentrate in a co-solvent to be later diluted with oil. Wood treatingsolutions useful for treating poles, fence posts, pilings and otherunfinished wood contain from about 1% to 50% pentachlorophenol andgenerally about 5% pentachlorophenol; these percentages beingestablished from practice in the industry.

Many times it is desirable to incorporate minor proportions of othercompounds into the treating solution to impart certain properties to thewooden material being treated. These compounds may include cosolventssuch as mineral spirits, waxes such as paraffin wax, resins such asrosin esters and modified rosin esters, surfactants like polyethoxylateddiamines and antioxidants such as di-tert butyl para-cresol and aminesand the like.

Solutions containing pentachlorophenol and petroleum hydrocarbons soondarken and form a sludge after being prepared thus requiring filteringor decanting prior to being used to treat wood. Furthermore, thesesolutions darken the surface of the wood during the heating and boilingperiods of treating and leave extremely dark greasy surface depositsuponthe treated object. In addition the treating mixture continues to darkenin use and a carbon type sludge develops and builds up in the woodtreating apparatus. This necessitates frequent interruptions ofoperation to clean out the apparatus and dispose of this foul smellingsludge.

When such treatment is applied to power line or utility poles, theproduct is not pleasing to the eye and detracts from the natural beautyof the surrounding area.

It is therefore an object of this invention to provide a method fortreating and preserving wooden objects which exhibits none of theforegoing characteristics.

Another object of this invention is to provide a method for producingand preserving light colored wooden objects through the use of a newwood treating composition.

Yet another object of this invention is to provide a method for treatingand preserving wooden objects and sludge formation is reduced.

Further objects and the entire scope of applicability of the presentinvention will become apparent from the detailed specification andexamples given hereinafter; it should be understood, however. that thedetailed specification and specific examples while indicating preferredembodiments of the invention are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art.

It has now been found that these and other objects can now be achievedby simply treating wooden objects with a wood treating and preservingcomposition comprising a blend of (I) a blend of (A) from about I% toabout 50% by weight of pentachlorophenol and (B) from about 99% to about50% by weight ofa petroleum hydrocarbon and (II) from about 0.005% toabout 100% by weight, based upon the total weight of (l) of a compoundcontaining a member of the class of elements classified in Groups 18,HA, IIB, IVA, IVB, VIA, VIB, VIII of the Periodic Table.

The wooden objects subject to treatment by this method are very light incolor and the treatment composition itself is extremely stable againstdiscoloration and sludge formation. I

Results obtained through this invention are surprising and quitedramatic. Example IV shows the improved performance of the wood treatingcompositions dis closed herein. Additionally, Examples I and IIdemonstrate the efficiency of these wood treating compositions indrasticly reducing or eliminating sludge and discoloration of thetreating solution during treatment.

The new method for treating and preserving Wood disclosed by thisinvention centers upon the use of compounds containing a member of theclass of elements classified in Groups IB, IIA, IIB, IVA, IVB, VIA, VIBand VIII of the Periodic Table in conjunction with pentachlorophenol anda petroleum hydrocarbon; with or without additives such as co-solvents,waxes, resins, decolorants, surfactants, inhibitors and stabilizers;such additives being well known in the art.

Advantages gained through the use of this method for treating wood areseveral fold. The wooden objects themselves are very light in appearancewhich is quite surprising, since heretofore any wooden objects treatedwith oil solutions containing pentachlorophenol have been extremely darkand in the majority of cases are greasy black due to sludge formed bythe treating solution itself and carried into the wood. It has, up tonow, been taken for granted this was normal for that this type oftreatment and could not be overcome. Wooden objects treated by thisinvention are dry to the touch, not greasy and are light in appearance.

Sludge formation and discoloration of the treating composition duringthe treating process are also problems associated with pentachlorophenolpetroleum hydrocarbon wood treating compositions. As with the problem ofwood discoloration, this has become an aceepted fact in the art and ithas been thought that such problems could not easily be overcome,especially when heavy petroleum solvents were used. It is now possible,through use of the method of this invention to prevent or practicallyeliminate sludge formation and discoloration of the treating solutionboth during storage and during the actual treating process. Theexperiments comprising Example I are designed to rapidly promote theformation of sludge and discoloration. However. comparison of the factspresented therein indicates the superior performance of this method.These results are also obtainable on a commercial scale as demonstratedin Example I\'.

Practiced in a general way this method involves treating wooden objectsby conventional means under heat and pressure with a treating andpreserving composition comprising (I) a blend comprising (A) from about1% to about 50% by weight pentachlorophenol and (B) from about 99% toabout 50% by weight a petroleum hydrocarbon and (II) from about 0.005%to about 100% by weight based upon the weight of(I) ofa heavy metal suchas titanium or a heavy metal containing compound such as titaniumdioxide.

The component (1) may also contain additional cosolvents, waxes, resins.decolorants, surfactants, inhibitors stabilizers and the like as isdesired and used in the art.

Wood treating compositions containing pentachlorophenol dissolved inpetroleum hydrocarbon are well known in the art. They may contain fromabout 1% to about 50% by weight pentachlorophenol and from about 99% toabout 50% of a petroleum hydrocarbon. For the practice of this inventionit is preferred that the solution be a blend of (A) from about 1% to byweight pentachlorophenol and (B) from about 99% to about 90% petroleumhydrocarbon. The petroleum hydrocarbon may be varied and includes dieseloil, kerosene, Nos. 1, 2 and 3 fuel oils, low, medium and high aromaticoils and the like and mixtures thereof.

To this blend may be added various co-solvents such as mineral spirits,aromatic hydrocarbons, glycols, and the like, waxes such as paraffinwax, resins such as rosin esters and modified rosin esters, surfactantslike polyethoxylated diamines and corrosion inhibitors and stabilizerssuch as di-tert-butyl-cresol, bis (Z-hydroxyethyl) cocoamine and thelike and decolorants such as diethyl oxalate. It has also been foundthat silicon dioxide is a useful additive to promote stabilizationagainst discoloration and sludge formation. These additives may be usedin amounts ranging from about 0.01% to about 1% by weight based upon thetotal weight of (A) and (B). The value of 1% by weight is merely apractical upper limit. However, greater amounts of these additives maybe used if preferred.

Component II of the wood treating composition is a compound containing ametallic member of the class of elements classified in Groups 18, IIA,IIB, IVA, IVB, VIA, VIB, and VIII of the Periodic Table. This wouldinclude the elements copper. silver, gold, zinc, cadmium, germanium,tin, lead, titanium, zirconium, hafnium, iron, cobalt, nickel,ruthenium, rhodium, palladium. osmium, iridium and platinum. Theseelements may be employed in their free metallic state ie. the metalitself or as an inorganic metallic compound. The preferred metals aretitanium, lead, tungsten, iron, chromium, tin, silver, and cobalt andinorganic compounds containing these such as titanium mono-oxide,titanium dioxide, titanium silicate, titanium diboxide, lead oxide,stannic oxide, silver oxide. chromium oxide, cobaltic oxide, tungstentrioxide, iron oxide and the like and mixtures thereof. The amount ofthe heavy metal compound used may range from about 0.005% to about 100%by weight based upon the total weight of (A) and (B) used. It should benoted that more than 100% by weight might be employed but would serve nopractical purpose. The preferred amount of the heavy metal compound usedranges from about 0.005% to about 1% by weight and most preferablybetween about 0.01% to about 0.18% by weight based upon the total weightof (A) and (B) employed.

Wooden structures to be treated via the method of this invention arewithout limit and may be defined any wooden form which requiresprotection against attack by weathering, fungus, insects and pestsincluding mill work. utility poles, fence posts, piling timbers and thelike.

A typical method for producing and preserving very light colored polescomprises placing wooden poles ranging from dry to green in varioussizes ranging from 6 inches in diameter and 12 feet in length to 20inches in diameter and feet in length in a retort 7 feet in diameter andfeet long. The additives of our invention are dispersed in a smallamount of oil and then added to the treating mixture containing about 5%pentachlorophenol. This mixture is pumped into the retort until thepoles are covered. During the seasoning period, the temperature of theoil treating mixture is increased to and maintained at about 220F under24 inches of vacuum for a period of time until the sapwood moisturecontent of the poles is reduced to approximately 10% this may take up toabout 50 hours. At the conclusion of the seasoning (or drying) cycle,the treating solution is withdrawn from the retort and initial air isintroduced to 30 PSI and maintained for V2 hour. Then the same treatingmixture is re-introduced with the 30 lbs. pressure retained so that airwould not escape from the wood until the retort is completely filled.Additional pressure is applied and the solution forced into the wood tothe proper depth at about F. Then the pressure is released and a vacuumapplied. This boiling period is called the expansion bath and ismaintained for about 2 hours. After the expansion period the treatingmixture is pumped from the retort and a final vacuum is applied for 1hour.

The poles are then removed from the retort and inspected for surfacedeposits and color. The treating mixture typically comprises a blend of(l) a blend of (A) about 5% by weight pentachlorophenol and (B) about95% by weight of a medium aromatic petroleum hydrocarbon oil and (11)about 0.05% by weight based upon the total weight of (A) and (B) oftitanium dioxide. This treating mixture also contains about 0.05% byweight based upon the total weight of (A) and (B) of di-tertiary butylpara-cresol and about 0.16% by weight, based upon the total weight of(A) and (B) of bis (2-hydroxyethyl) cocoamine.

This invention will be more readily understoodby reference to theaccompanying specific examples which are intended as illustrative onlyrather than as limiting the invention except as defined in theaccompanying claims.

Although only a limited number of solvents and cosolvents have beendescribed in the examples in connection with formulation of the treatingmixtures embodying the present invention, the latter is not limited tothe use of any particular solvent or co-solvent. The present inventionbroadly provides the means to counteract the sludge-forming andwooddarkening color tendencies inherent in wood-treating formulations.

The practice of our invention is not limited by any particular treatingtemperature except those temperature ranges outside of practicality.

Four methods were used for the experimental evaluation of the effects ofthe additives of our invention on wood-treating mixtures and on thetreated wood:

A. The 30-day test.

and Western red cedar heartwood chips. In addition. various four-pennyfinishing nails and 5 mls. of water were then added. The flask was thenstoppered with a cork which has a 6 in. glass tube inserted through itto B. The 90-minute test. 5 act as condenser and vent. This was thenplaced into a C. The experimental retort test. 240F carnuba wax bath toa depth of 1 /2 in. and the D. The experimental commercial retort test.water allowed to flux for 30 days.

Upon completion of the 30 days,'the contents of the EXAMPLE l flask wereimmediately filtered through a Schleicher l and Schuell No. 588, 24 cm.filter paper. The filtered Results using the 30-Day Test Pmcedure 1m: Pmixture was not only retained for color tests but also to ented in TableI. In the Table, control experiments are d t ine th r lative amount oftar-like sludge which compared to the test experiments. the formulationis i h i it t upon cooling. The remaining solids de$CfibedandObservations ahd fe$llh$ lire noted- This were washed with acetone todetermine the amount of test evaluates the effectiveness of theadditives of our l5 i l bl l d d t ob erve the condition of theinvention as stabilizers for oil-treating mixtures and as WOOCL to theeffect on the condition of the treated wood. A Th l r test is performedby placing 4 drops of the technical description of the y Test is givenbelow? filtered solution in a Gardner test tube and then filling The yTest to the line with acetone. After shaking. the mixture was The testwas conducted by dissolving 7.8 grams of 20 tested on the Gardner ColorScale pentachlorophenol in 142.2 grams of the oil to be Th l d ai ing onthe filter paper was graded tested in a 250 ml. Erlenmeyer flask. Inaddition, variaccording to visual examination from extremely light in Hadditives B C miXed in s needed- The niu amount to very heavy in amount.Also. the color of the compounds or other metal compounds were dispersedsludge was noted. in a small amount of oil prior to mixing with the restof The wood condition was graded according to lthe treating solution.The mixture was then heated to ex ellent; 2-good; 3-fair and 4-poor. Thewood condi- 300F for 90 minutes followed by the addition of 7 tionrelates to wood color and sludge deposits on the grams each of Ponderosapine and Douglas fir sapwood surface of the wood.

TABLE I EYAl'LAllON ()F ADDl'llYES IN WOOD TREATlNG MIXTURES FOR THE30-DAY TEST Formulation of Test Results 'lreating Mixture Color RatingWood Experiment No. Parts by Sludge Observation of Treating ConditionMaterial" Wgt. in gins. Mixture Rating A (Control) PCP 7.800 Mediumamount sludge and dark in l l 4 Oil A 139.400 color. L'CON solvent 2.800

B (Test) PCP 7.800 Medium amount sludge and dark 8 1-4 Oil A 139.400brown in color. UCON solvent 2.800 Ti(). 0.021

C (Test) PCP 7.800 Medium amount of sludge and dark 8-) -4 Oil A 139.400ll\()\\l1 in color. l'CON solwnt 2.800 'l'i(). 0.071

D (Test) PCP 7.800 Medium amount of sludge and 6 2-3 Oil A 139.400 lighttan in color. UCON solvent 2.800 TiO. 0.284

E (Test) PCP 7.800 No sludge 2 l Oil A l39.-l-00 LCON solvent 2.800 TiO.50.000

F (Test) P('P 7.800 No sludge 3 l Oil A 139.400 L'CON solvent 2.800Ti()- l50.00()

A (Control) PCP 7.800 Medium amount of sludge and dark 9 4 ()il Al42.200 in color. Medium amount tar formation.

B ('lest) PCP 7800 Light amount sludge and grey in 5 2 ()il A l42.200color. No tar formation. DTBC 0. l TiO. 0.070

A (Control) PCP 7.800 Medium amount sludge and dark 1 l 3 ()0 A l H.000colored. Base A 28.000

B t'l'est) PCP 7.800 Extremely light amount oi sludge 8 l-2 ()il A lH.200 and light in color. Base A 28.000 Ti(). 0070 D'IBC 0. l 50 TABLE 1Continued Formulation of Test Results lreating Mixture Color Rating Woodlzvperinient No. Parts I Sludge ()hservation ot"lreating ConditionMaterial" V1 gt. in gms. Mixture Rating A (Control) PCP 7.500 Mediumlight sludge and dark in 14-15 g 3-4 ()il H 142.300 eolor. Amine A (L1004 B ('l'cs't) PCP 7.800 Light amount of sludge and dark I I I3 ()il B142.100 gt'e} in color. Amine A 0.100 't'i(). 0.070

A (Control PCP 7.800 Medium amount olsludge I l 4 ()il A 139.400 anddark in color. L'CON solvent 2..400

B ('l'es'tl PCP 7.800 Medium amount of sludge N 3 Oil A 139.400 and \ervdark. [CON solvent 2.800 '1'i() .021 D'I'BC 0,050

C (Test) PCP 7.800 Medium amount of sludge o 2 ()il A 13 L400 andtan-grey in color.

L'CON solvent 2.800 T10: 0.284 DTBC 0.050

D (Test) PCP 7.800 l-Ixtremelv light amount of 10-1 1 2-} ()il A 139.400sludge and light gre v in L'CON solvent Z..\'00 color. Ti(). 0071 DII'BCl0,0()() "Definition of materials: PCP pentuehloriiphenol. D'IHC Idi-terti;tt' \|tlt)l para-eiesol'. Iii titanium dio\ide; amine ()1! HHusk oil. medium aromatic oil su plied h Husk )il ('11.; Oil Shell No.

hx Standard Oil ol'Caliliu'nia EXAMPLE 11 Results using the 90-MinuteTest procedure are pres- 35 l'niun Carbide (0.100 A PS 300. [on aromatieoil supplied l 'l ime i] ('u.;

I diesel oil. upplied I Shell Oil Cu. liaise aromatic nil supplied ofoil contained in a 125 ml. Erlenmeyer flask. Additives were mixed in asdesired. The titanium dioxide or other metal compounds was firstdispersed in a small amount of oil prior to mixing with the rest of thetreating mixture.

The control and test samples were placed in an oven at 300F for 90minutes and then removed and cooled.

The cooled mixture was filtered through a No. 40 Whatman filter paper.

Evaluation of the effect on the oils was performed in the following way:The sludge remaining on the filter paper was graded as to amountaccording to visual examination: that is. as light. medium. heavy and asvariations of these. Also. the color of the sludge was noted.

TABLE 11 EVAULATION OF ADDl'llYl-IS IN WOOD TREATING MIXTL'RES BY THEJO-MINUTE TEST Formulation of 'l'reating Mixture Test Results ColorRating Experiment No. Parts by Sludge Observation of Treating Materlal"Wgt. in gms'. Mixture A (Control) PCP 10.000 Heavy amount of sludge andblack in 7-H Oil D 90.000 color.

B (Test) PCP 10.000 Heav amount of sludge and grey in 6-7 ()i] D 00.000llttltit'v Ti(). (1.07)

C (Test) PCP 10.000 \'er light amount of sludge and gre} 7 ()il 1)00.000 in color. Amine A 0.030 'li(). 0.071

1) (Test) PCP 10.000 Yer light amount sludge and light 6-7 ()il 1)90.000 grey in color. Amine A 0.030 DTBC 0.150 Ti(): 0.07]

EYALLATlON OF ADDlTlYES lN \NOOD TRFA llNG MlXTT'RliS BY lHF.)(l-MINL'TE TEST Formulation of Treating Mixture Test Results ColorRating Experiment No. Parts by Sludge Observation of Treating Material"Wgt. in guts. Mi t A (Control) PCP l0.000 \ery light amount of sludgeand black ll 3 Oil B 90,000 in color. Amine A 0.030

B (Test) PCP l0.000 No sludge l3 Oil B 90.000 Titanium 0.l00

metal Amine A 0.020

A (Control) PCP l0.000 Heavy amount of sludge and dark colored. I4

Oil B 90.000

B (Test) PCP l0.000 No sludgev l3-l-l ()ll B 90,000 TlO 0.000 3 C (Test)PCP l0.000 Medium amount sludge and grey in color. [4

Oil B 90.000 Titanium silieate 0.0(10

D (Test) PCP l0.000 Medium amount sludge and grey in color. l3-l-l ()llB 90.000 Titanium dihoride 0.060 A (Control) PCP l0.000 Heavy amountsludge and dark in color. (1

Oil D 90.000 4 B (Test) PCP l0.000 Medium amount sludge and light grey 4()il D )0.000 in color. TiO: 0.07] Tertiaryhutyl hydroquinone 0.05

4 C (Test) PCP l0.000 Extremely light amount sludge and 5 Oil l) 90.000light grey in color. 'l'i() 0.07] Ethoduomeen T- l 3 0.030

A (Control PCP 10.000 Light-medium amount of sludge and 6-7 Run at 12F()il B 90000 black in color. q

B (Test) PCP l0.000 Light-medium amount of sludge and (1 Run at l22F OilB 90.000 grey-green in color.

A (Control) PCP l0.000 Medium amount of sludge and black 9 l0 Run at2l2F ()il B 90.000 in colorv 6 B (Test) PCP 10.000 Medium amount ofsludge and greyh Run at ZITF Oil B 90.000 green in color.

TiO: 0.07]

A (Control) PCP l0000 Medium-hea y amount of sludge and l l-l 2 R at356) Oil B 00.000 black in color. 7

B (Test) PCP l0.000 Very light amount of sludge and I1 Run at 356F Oil B90.000 light grey in color.

Ti() 0.07l Ethoduomeen 0.030 T-l3 A (Control) PCP l0.000 Medium-heavyamount of sludge and l l-l 2 Oil B 90.000 black in color. X B (Test) PCPl0.000 Light amount of sludge and buff 1] Oil B 90.000 colored. PhO0.070 C (Test) PCP l0.000 Medium heavy sludge and dark grey l l-l2 Oil B)0.000 in Colo). Sn(). 0.070

D (Test) PCP l0.000 Medium-hea y amount of sludge and l l-l2 Oil B90.000 grey-brown in color. Ag O 04070 E (Test) PCP l0.000 Medium amountof sludge and dark in l0-l 1 Oil B 90.000 color. Si0. 0. I00

F (Test) PCP l0.000 Medium hea\ y amount of sludge and l l-] 2 Oil B90.000 green in color. Cr. .O 0.070

Formulation of 'l'est Results l'reating Mixture Color Rating l-\pernnentNo Parts by Sludge ()hsenation ol' lreating Material Wgt. in gms.Mixture (Test) PCP 10.000 Medium-heavy amount of sludge and I 1 Oil B90.000 black in color. c0 0.

H (Test) PCP l0.000 Medium-heavy amount of sludge and l l-lZ Oil B90.000 dark grey in color. W0 0.070

I ('l'est) PCP 10.000 Medium heavy amount ot sludge and 1-11 Oil B90.000 red-brown in color. Fe O 0.070

aromatic petrolen para-cresol; 'l i oil supplied by Mobile Oil to. Aminetium niono xide: etlioduomeen 'l l 3 EXAMPLE III Results using the PilotRetort Test procedure are presented in Table lll. This test evaluatesthe effectiveness of the additives of our invention as stabilizers foroil treating mixtures and as to their effect on the condi tion oftreated wood. The retort and accessories is actually a wood-treatingpilot plant. In the table, a control experiment is used to compareagainst the test experiments. the formulation is described. andobservations made in regard to the treated poles. A technicaldescription of the Pilot Retort Test procedure is given below:

C. Experimental Retort Test Definition of materials: PCPpentaehloroplienol: Oil B medium aromatic petroleum oil supplied byHuskey il (1 )il l) 1 ('ertre\ 500. medium l is(Z-hydrmyethyl)eoeoamine; 'l it) titanium dioxide. Dilit' di-tertiar \-hut \lurl'aetant tpolyetlioxylated diamine) supplied by Armour Industrial(hemical .1 PM) stannic oxide. \g- .O sil\ er oxide; SK) t icon dio\ide;(12 0 clu'oniie oxide: (of eolmltic o\ide: tungsten trio\ide:

"'l ests' 5. h and 7 were run at different temperatures than normallyrun in the HI-\linuie -l'cst to demonstrate u efulne s ol' the in\entionover a range of temperatures.

at 220F. under a 26 in. vacuum for a period of time until the sapwoodmoisture content of the posts were reduced to approximately 10%; thistook up to 36 hours. At the conclusion of the seasoning (or drying)cycle, the treating solution was withdrawn from the retort and initialair was introduced to 30 No. P.S.l. and maintained for /2 hour. Then thesame treating mixture was re-introduced with the 30 N0. pressureretained so that the air would not escape from the wood. Next the retortwas completely filled with treating mixture and additional pressure wasapplied and the solution forced into the wood to the proper depth at lF.When the proper amount of treating mixture had been forced into the wood(min. of the sapwood penetrated), the pressure was released and a vacuumapplied. This boiling period is called the expansion bath and it wasmaintained for two hours. After the expansion period the treatingmixture was pumped from the retort after which a /2 hour final vacuumwas applied. The posts were then removed from the retort and inspectedfor surface deposits and color as well as checking, etc. Comparisonswere then made between the controls and test pieces. When control runswere made. no additives were introduced into the treating mixture.

TABLE lll EVALUATION OF ADDlTl\'ES IN WOOD TREATING MIXTL'RES FOR THEPll.OT RETORT TESTS Formulation ol Test Results Experiment No. Parts byObservation of Poles Material" Wt. in lbs.

A (Control) PCP l).200 Medium amount of sludge and dark colored. PostUCON solvent 7000 surface dark on l side and medium dark on the Oil A354.000 other side.

B (Test) PCP W100 Light amount ol sludge and medium grey in color.

L'CON solvent 7000 Oil A 354.000 Wood posts have light grey color.

C (Test) PCP W100 No sludge was formed. Wood posts ha\e light L'CONsol\ent 7.000 amber color. ()il A 354.000 D l lfl 0.310 't'i0. 0.140

D (Test) PCP 19.100 No sludge. Wood surface color very light.

UCON solvent 7.000 Oil A 354.000 Amine A 0.070 H0: 0.220

EVALL'A'I'ION OF ADDITIVES ll\' WOOD TREA'I'INO MIXTURES FOR THE PILOTRi-ITORT TESTS Test Results Experiment No. Parts by Observation of PolesMaterial" Wt. in lbs.

A (Control) P('P 19.100 Some sludge and dark in color. Post surfaces OilB 3ol.000 dark in color.

B (Test) PCP W100 No sludge was formed. Post surfaces light Oil B3(il.000 beige in color. DTBC 0. I 90 TiO- 0.I7() Amine A 0.070 C (Test)PCP 19.100 No sludge was formed. Post surfaces light grev Used Oil B301,000 in color. DTBC U. l 90 no. uv I70 Amine A 0.070

A (Control) PCP 19.200 Medium heavy sludge and dark in color. Post 1 OilD 3OI.UUU surfaces darl; in color.

B (Test) P('P W100 No sludge. Post surfaces light tan in color.

()il D l.il(li) DTBC 0.190 TiO 0.170 Amine A 0.070

A (Control) PCP W100 Light sludge and dark in color. Post surfaces 4 OilE 3ol.000 dark brown in color.

B (Test) PCP 19.200 No sludge. Post surfaces light beige in color.

Oil E 36|.(J(1U DTBC 0.190 TiO 0.170 Amine A Delinition of material:P('P pcntachh\ropheuol; D'I BC di-tcrtiary-but \l para-crcsol: 'IiOtitanium dioxide; Amine A bis( 2-hydrox \cth \l) cucoaminc; Oil A PS200. low aromatic oil supplied by Time Oil (11.: Oil B Husky Oil. mediumaromatic oil supplied h Husk Oil Co; Oil D ('er'trc.\.50('. mediumaromatic oil supplied l1 Mobile Oil (0.1 Oil E Shell Chemical Co.

'I'l No.1. medium aromatic oil supplied by Shell ('hemical ('o.

EXAMPLE IV Results using an Experimental Commercial Treating Plantmethod are presented in Table IV in which a control experiment is usedto compare against the test ex periments. the formulation is describedand observations made in regard to the treated poles.

This test evaluates the effectiveness of the additives of our inventionas stabilizers for oil treating mixtures and as to their effect on thecondition of the treated wood on a large scale. A technical descriptionof this procedure is given below.

D. Experimental Commercial Retort Test The American Wood PreserverssAssociation procedures were used. Wooden poles ranging from dry to greenin various sizes ranging from 6 inches in diameter and 12 feet in lengthto 20 inches in diameter and 100 feet in length were placed in a retort7 feet in diameter and 120 feet long. The additives of our inventionwere dispersed in a small amount of oil and then added to the treatingmixture containing 57: pentachlorophenol. This mixture was pumped intothe retort until the poles were covered. During this seasoning period.the temperature of the oil treating mixture was increased to andmaintained at 220F under 24 inches of vacuum for a period of time untilthe sapwood moisture content of the poles were reduced to approximately10%; this took up to 50 hours. At the conclusion of the seasoning (ordrying) cycle. the treating solution was withdrawn from the retort andinitial air was introduced to 30 PSI and maintained for /2 hour. Thenthe same treating mixture was reintroduced with the 30 lbs. pressureretained so that air would not escape from the wood until the retort wascompletely filled. Additional pressure was applied and the solutionforced into the wood to the proper depth at F. Then the pressure wasreleased and a vacuum applied. This boiling period is called theexpansion bath and was maintained for two hours. After the expansionperiod the treating mixture was pumped from the retort and final vacuumapplied for one hour.

The poles were then removed from the retort and inspected for surfacedeposits and color as well as checking, etc. Comparisons were madebetween the controls and test pieces. When control runs were made, noadditives were introduced into the treating mixture.

TABLE IV EVALUATION OF ADDITIVES IN WOOD TREATING MIXTURES FOR THEEXPERIMENTAL COMMERCIAL RETORT TESTS Formulation of Treating MixtureExperiment No. Parts by Test Results. Observation of Material Weight inlbs. Treated Poles A (Control) PCP 9.360 Medium-heavy amount of sludgeand black in il D l7 .(i40 color. Pole surface dark.

B (Test) PCP 9.360 No sludge observed. Pole surface light Oil D l7(i.0-ill amber DTBC )3 Amine A 30 'fi() )0 TABLE Continued EYALlA'l'lON ()F.-\l)l)l'll\ l-'S ll\' )l) I RFA'I'ING MlX'll 'RFS FOR ['Hl' l'..\ll'll.\1l .\"l':\l ('()l\ll\l1:R(l.\l Rl-"IOR'I TESTS lln'iillllalinll ul '1renting Mixture Experiment No. Paris by lo\l Results. ()hsenatiun ofMaterial eight in llis. Treated Poles A (Control) PCP L300 Medium amount01' sludge and black in color.

()il A M7180 pU L' surface dark. l'('(),\ when! 3.300

B ('l'est) PCP .3 0 \o sludge obscn ell. Pole surface licigc color.

011 A 107.280 l('().\' \olwnt 3.300 l)'] BC )3 Amine A 'l'i(). an

"Definition of material: PCP peliluclilurnphcnl l: l)ll(' \Ii-Iertiarlulyl ;|l.l Cl'\ l li()- titanium diinidc; amine lns What is claimed is:

l. A method for production of light colored wooden structures whichcomprises impregnating said wooden structures under pressure and vacuumwith a composition comprising a blend of (l) a blend of (A) from about1% to about 50% by weight of pentachlorophenol and (B) from about 99% toabout 50% by weight ofa petroleum hydrocarbon and (11) from about 0.005%to about 100% by weight. based upon the total weight of (A) and (B), ofa member of a group consisting of metals selected from the class ofelements classified in Groups 18, HA, 118. NA. lVB. VIA, VlB. and VIIIof the Periodic Table and oxides thereof.

2. A method for production of light colored wooden structures as definedin claim 1 wherein I1 is a member of a group consisting of metalsselected from a group consisting of titanium. lead. tungsten. iron.chromium, tin. silver. and cobalt and oxides thereof and removing excesspetroleum hydrocarbon from the impregnated wooden structures.

3. The method for production of light colored wooden structuresaccording to claim 1 wherein (11) is a metal oxide.

4. The method for the production of light colored wooden structuresaccording to claim 2 wherein (11) is at least one member selected fromthe group consisting of titanium dioxide. titanium oxide. titaniumdiboride. lead oxide. stannic oxide. silver oxide. chromic oxide.cobaltic oxide. tungsten trioxide and iron oxide.

5. The method according to claim 2 wherein (II) is at least one metalselected from a group consisting of titanium. lead, tungsten. iron.chromium. tin. silver. and cobalt.

6. The method for the production of light colored wooden structuresaccording to claim 1 wherein (1) is a blend of(A) about 1% to about 10%by weight pentachlorophenol and (B) about 99% to about by weightpetroleum hydrocarbon oil.

7. The method for the production of light colored wooden structuresaccording to claim 2 wherein the amount of (11) used ranges from about0.01% to about 0.18% by weight based upon the total weight of (A) and(B) used.

8. The method for the production of light colored wooden structuresaccording to claim I wherein from about 0.01% to about 0.1% by weight ofbis (2- hydroxethyl) cocoamine is added to (l).

9. The method for the production of light colored wooden structuresaccording to claim 1 wherein from about 0.01% to about 1% by weight ofdi-tertiary-butyl para-cresol is added to (l).

10. The method for the production of light colored wooden structuresaccording to claim 1 wherein from about 0.01% to about 1% by weight ofsilicon dioxide is added to (1).

11. The method for the production of light colored wooden structureaccording to claim 1 wherein cosolvents. waxes. resins. decolorants.surfactants. and inhibitors and stabilizers are added.

12. The method for the production of light colored wooden structuresaccording to claim 1 wherein the amount of co-solvents. waxes. resins.decolorants. surfactants and inhibitors added ranges from about 0.01%

to about 1% by weight.

1. A method for production of light colored wooden structures whichcomprises impregnating said wooden structures under pressure and vacuumwith a composition comprising a blend of (I) a blend of (A) from about1% to about 50% by weight of pentachlorophenol and (B) from about 99% toabout 50% by weight of a petroleum hydrocarbon and (II) from about0.005% to about 100% by weight, based upon the total weight of (A) and(B), of a member of a group consisting of metals selected from the classof elements classified in Groups IB, IIA, IIB, IVA, IVB, VIA, VIB, andVIII of the Periodic Table and oxides thereof.
 1. THE METHOD FOR THEPRODUCTION OF LIGHT COLORED WOODEN STRUCTURES ACCORDING TO CLAIM WHEREINTHE AMOUNT OF COSOLVENTS, WAXES, RESINS, DECOLORANTS, SURFACTANTS ANDINHIBITORS ADDED RANGES FROM ABOUT 0.01% TO ABOUT 1% BY WEIGHT.
 2. Amethod for production of light colored wooden structures as defined inclaim 1 wherein II is a member of a group consisting of metals selectedfrom a group consisting of titanium, lead, tungsten, iron, chromium,tin, silver, and cobalt and oxides thereof and removing excess petroleumhydrocarbon from the impregnated wooden structures.
 3. The method forproduction of light colored wooden structures according to claim 1wherein (II) is a metal oxide.
 4. The method for the production of lightcolored wooden structures according to claim 2 wherein (II) is at leastone member selected from the group consisting of titanium dioxide,titanium oxide, titanium diboride, lead oxide, stannic oxide, silveroxide, chromic oxide, cobaltic oxide, tungsten trioxide and iron oxide.5. The method according to claim 2 wherein (II) is at least one metalselected from a group consisting of titanium, lead, tungsten, iron,chromium, tin, silver, and cobalt.
 6. The method for the production oflight colored wooden structures according to claim 1 wherein (I) is ablend of (A) about 1% to about 10% by weight pentachlorophenol and (B)about 99% to about 90% by weight petroleum hydrocarbon oil.
 7. Themethod for the production of light colored wooden structures accordingto claim 2 wherein the amount of (II) used ranges from about 0.01% toabout 0.18% by weight based upon the total weight of (A) and (B) used.8. The method for the production of light colored wooden structuresaccording to claim 1 wherein from about 0.01% to about 0.1% by weight ofbis (2-hydroxethyl) cocoamine is added to (I).
 9. The method for theproduction of light colored wooden structures according to claim 1wherein from about 0.01% to about 1% by weight of di-tertiary-butylpara-cresol is added to (I).
 10. The method for the production of lightcolored wooden structures according to claim 1 wherein from about 0.01%to about 1% by weight of silicon dioxide is added to (I).
 11. The methodfor the production of light colored wooden structures according to claim1 wherein co-solvents, waxes, resins, decolorants, surfactants, andinhibitors and stabilizers are added.